Apparatus for regulating combustion



July 23, 1929. G. wUNscH APPARATUS FOR REGULATING COMBUSTION Filed Nov. 25, 1927 J0 zren Z02 Guido 20W 15 Patented July 23, 1929.

UNITED STATES PATENT OFFICE.

GUIDO WfiNSCH, OF STEGLITZ, NEAR BERLIN, GERMANY, ASSIGNOR To ASKANIA- WERKE AKTIENGESELLSCHAFT VORMALS CENTRALWERKSTATT DESSAU UNI) CARL BAMBEBG-IRIEDENAU, F BERLIN-FRIEDENAU, GERMANY.

APPARATUS FOR REGULATING COMBUSTION.

Application filed November 25, 1927, Serial No. 235,710, and in Germany september 23, 1926.

This invention relates to an apparatus for regulating combustion. In most cases, the principle underlying combustion regulators consists in maintaining a certain ratio between the outflowing waste gases (or the iuflowing volume of air) and the amount of fuel supplied. A disadvantage of this method is that the calorific valueof the fuel may change (for example, when the nature of .the coal changes) with the consequence that the proportion of CO in the waste gases The boiler pressure prevailing in a steam pipe 1 is transmitted through a pipe 2 to. a diaphragm 3which is extended or contracted in accordance with the rising or falling pressure in the pipe 1. The diaphragm is provided with a contact rod 4 connected to a jet tube 5, i. e., a tube through which a medium under pressure such as compressed air or the like continuously flows. The jet tube is suitably acted upon by a spring 6 balancing the pressure within the diaphragm 3. The ends of two pipes 8 and 9 are disposed in front of the mouth of the jet tube 5 adapted to pivot about a stationary point 7, so that the compressed-air or any other pressure medium discharged from said jet pipe may enter the one or the other of the pipes 8 and 9 according to the position of the jet pipe. The pipes 8 and 9 lead to chambers 10 and 11: respectively, of a difierential pressure gauge, the diaphragm 12 of which is connected to a second jet tube 13 also continuously traversed by a pressure medium and adapted to pivot about a stationary; point 13. The said pressure gauge is opposite to another differential pressure gauge 14,.the vtwo chambers of which are connected-with pipes 15 and 16 respectively opening into a flue 18, one on either side of a perforated partition 17 or the like disposed therein, the waste gases, the quantity of which corr'e'.

sponds essentially to the quantity ot the inflowing combustion air flowing through the said flue. The diaphragm 19 of the differential pressure gauge 14 is connected by means of a rod 20 to a lever 21 disposed in the vicinity of the jet tube 13 and adapted to oscillate about a point 22. A sliding block 23 may be longitudinally moved (for example, with the aid'of a handle 24) between the lever 21 and the jet tube 13 so that the oscillating movement of the lever 21 is transmitted to the jet pipe 13 in a variable ratio according to the position of the sliding block 23, as by the adjustment of said sliding block the lever arms of the lever 21 and the jet tube 13 vary. The ends of two pipes 25 and 26 are disposed under the mouth of the jet tube 13 and lead to the ends of a cylinder 27 respectively, the piston 28 of the said cylinder moving together with a sliding damper 29 disposed in the flue 18. The arrangement described up to this point is well known since it is disclosed in applicants U. S. Patent No. 1,558,529.

In addition to the regulating means just described, the apparatus comprises twotfur ther difierentialpressure gauges 30 and 31 the diaphragms 32 and 33 of which are connected by rods 32 and 33 to a jet tube 34 adapted to pivot about a stationary point 34 and being also traversed by a pressure medium and a lever 35 swinging about a pivot 35 respectively. Between said tube 34 and lever 35 a sliding piece 36 is adapted to be moved' longitudinally so that the oscillating motion of the lever 35 is transmitted to the tube 34in a changin ratio in accordance with the position of t e sliding piece 36 as described above in connection with the sliding piece 23. The differential pressure gauge 31 is o erated b the amount of fuel supplied; orexamp e, in the case of a gas-fired apparatus, the two pressure chambersof the gauge 31 are connected by means of pipes 38 and 39 to two points, separated by a perforated partition 47 of the fuel-supply p pe 48. In a coal-fired apparatus wlth a moving grate, pressure in accordance the rate of coal supply is produced by means of a pump 49 driven by the grate drive so that the air pressure produced by said pump corresponds to the velocity of the grate motion pressure chamber of the said pump 49 by means of a pipe 50, while the other chamber.

opens to the. atmosphere, as indicated in the drawing by pipe 52. The second differential pressure gauge 30 is connected by two pipes 40 and 41 to the pipes 15 and 16. .y vTwo pipes 42 and 43 are disposed under the opening of the jet tube 34 and lead to the ends of a cylinder 44 respectively, the piston 45 of the said cylinder being used for controlling the supply of fuel to the furnace of the boiler. This may be done in the case of a gas-fired apparatus, for example, by means of a damper 51 inserted into the fuel pipe 48 and controlled by the rod 45 of the piston 45 and in the caseof a coal-fired apparatus, for example, with the aid of a switch 46 controlling the supply of the electric current supplied to the motor driving the grate.

The last described apparatus therefore corresponds essentially to that first described, but, the first described apparatus serves for adapting the combustion air or the waste gases to the produced steam, while the last de- 25. scribed apparatus serves, for adapting the fuel tothe combustion air or to the waste gases.

As long as the slide piece 36 rests in its position, therefore, the ratio of waste gases and fuel remains constant and the supplied air and fuel remain in accordance with the produced steam.

Now, according to the invention, the said ratio should be adjusted in accordance with the nature of the waste gases, especially in accordance with the proportion of CO in the waste gases.

For this purpose, according to the invention, the adjustment of the sliding piece 36 is to be eflectedin accordance with the alteration of the proportion of CO in the waste gases flowing through the flue 18. For this purpose, a C0 meter 37 'of any suitable and own construction is provided, the member of which, moved in accordance with the alteration of the CO ratio, is connected to the slide piece 36 by means of a rod 36 so that said slide piece is adjusted in accordance with the oscillations of a C0 meter 37 con- 5 nected to the flue 18 by means of the pipe 37. The apparatus operates as follows: The pressure prevailing in the pipe 1 acts updn the diaphragm 3and fluctuations in the said pressure together with the spring 6 cause the jet tube 5 to oscillate one way or the other, for the purpose of varying the amount of compressed air flowing into the pipes 8 and 9 and producing a difference between the pressure in the chamber 10 and that in .the chamber 11. This difference in pressure acts upon one side of the jet tube 13, the other side of which is acted upon by the waste gases through the medium of the diaphragm 19 bf the differential pressure gauge 14. The.

05 lever 21 and the sliding blocks 23 disposed between the lever 21 and the jet tube 13, serve the purpose of adjusting the ratio of trans mission of movement-between the two diaphragms 12 and 19. When the thrust on one side of the jet tube 13 is greater than on the other, the said tube oscillates about its stationary pivot so that. more or less compressed air flows into the pipes 25 and 26, with the result that the piston 28 moves to the right or to the left together with the damper 29. As a consequence, the volumeof gases flowing through the flue 18 is increased or decreased and the difference in the pressure between the two faces of the diaphragm 32 of the differential pressure gauge 30 is altered for the purpose of oscillating the jet tube 34. This causes the piston 45 to move to the right or to tlfe left in order to operate the damper 51 or the switch 46 to increase or reduce the amount of fuel by increasing or decreasing the speed of the grate. The ratio between the volume of air or of waste gases and-the amount of fuel supplied thus remains constant at any load of the boiler provided the n1ovement-transmission ratio between the diaphragms 32 and 33 of the difierential I ssure gauges 30 and 31 remains unaltere' i. e. long as the position of the sliding piece 36 is unaltered, the said position being in accordance with the oscillations of the CO meter 37. When, however, the proportion of CO in the Waste gases is altered, (for example, when fuel of a higher or lower calorific value is being burnt), the said meter moves the sliding piece 36 in one or the other direction so that the movement-transmission ratio between the diaphragms 32 and 33 is altered, thereby altering the proportion of: fuel supplied relatively to the volume of waste gases. Thus, in any case, combustion is complete and therefore, the supply of heat is satisfactory.

. Of course, the invention is not limited to the construction just described, since other suitable means may be used for maintaining the ratio between the volume of air or waste gases and the amount of fuel supplied. The essential feature in any case is to alter this ratio automatically with the aid of a regulating device actuated in accordance with the nature of the waste gases. This device need not necessarily be a C0 meter but may be a device operated by the specific weight of the waste gases, or by their proportion of CO or b any of their properties.

The apparatus according to the invention may be used in conjunction with coal-fired, gas-fired, oil-fired or any type of furnaces.

I claim as my invention:

1. An apparatus for regulating combustion comprising a waste gas pipe, fuel supplying means, a further pipe through which. a compressed gas flows, means adapted to move said last mentioned pipe in opposite directions corresponding to the flow of the waste gases in said waste (gas pipe, and the flow of fuel supplied by sai suppl g means respectively, means operated by t e said medium escaping from said further pipe adapted to maintain a certain ratio between the flows of the fuel and the waste gases, and a device operated according to the composition of the waste gases and regulating the said ratio.

2. An apparatus for regulating combustion comprising a waste gas pipe, fuel supplying means, a further pipe through which a compressed gas flows, gauges influenced by the quantity of waste gases flowingin said waste gas pipe and by the quantity of fuel supplied by said supplying means respectively which move said last mentioned in opposite directions, means operated y the said medium escaping from said further pipe and adapted to maintain a certain ratio between the flows of .the fuel and the waste gases, and a device operated according to the composition of the waste gases and regulating the said ratio.

3. An apparatus for regulating combustion comprising a waste gas pipe, fuel supplying means, a further pipe through which a compressed gas flows, gauges influenced by the quantity of waste gases flowing in said waste gas pipe and by the quantity of fuel supplied by said supplying means respective- 1y which move said last mentioned pipe in opposite directions, an adjustable device afranged between one gauge and said further.

pipe adapted to change the ratio between the influences of the gauges on said further pipe, means operated by the said medium escaping from said further pipe and adapted to maintain a certain ratio between the flow of the fuel and the waste gases, and a device operated according to the composition of the waste gases and adjusting said adjustable device.

4. An apparatus for regulating combustion comprising a waste gas pipe, fuel supplying means, a further pipe throu h which a compressed gas flows, means a apted to move said last mentioned pi e in opposite directions corresponding to the flow of the waste gases in said waste gas pipe, and the flow of fuel supplied by said supplying means respectively, means operated by the said compressed gas escaping from said further pipe and adapted to malntain a certain ratio between the flows of the fuel and the waste gases, and a device operated according to the proportion of CO in the waste gases'and re lating the said ratio.

1 testimony whereof I have aflixed my signature.

sumo, W'UNSCH. 

